Throttle divider of fluid medium flow

ABSTRACT

A throttle flow divider having a floating slide valve in a body whose outlet channels are interconnected by means of a permanent hydraulic resistor which assists in increasing the accuracy of the flow division due to redistribution of the fluid medium from one working branch with a higher pressure to the other working branch with a lower pressure.

O United States Patent 1151 3,674,047

Tauger 1 July 4, 1972 154] THROTTLE DIVIDER 0F FLUID 2,242,002 5/1941 Klein 1 37/101 MEDIUM FLOW 2,283,266 5/1942 Kinsella ..137/101 [72] Inventor: Mikhail Borisovich Tauger, ulitsa Bauprimary Examine, R0bert G, il

mana, 27, kv. 20, Sverdlovsk, U.S.S.R. Atmmey Ho]man & S

[22] Filed: Sept. 4, 1970 [57] ABSTRACT [2]] App]. N0.: 69,609

A throttle flow divider having a floating slide valve in a body whose outlet channels are interconnected by means of a per- [52] US. Cl ..l37/10l, l37/1 l0 manent hydraulic resistor which assists in increasing the accui l 05d ll/03 racy of the flow division due to redistribution of the fluid [58] Field of Search ..l37/98, 101, 110, 118 medium from one working branch with a higher pressure to the other working branch with a lower pressure. [56] References Cited 2 Claims, 1 Drawing Figure UNITED STATES PATENTS 2,930,39l 3/1960 Bass et a]. ..137/1 1 PATENTEDJUL 4 M2 3, 574,047

IarEMTQA, M! ,BMW

THROTTLE DIVIDER OF FLUID MEDIUM FLOW BACKGROUND OF THE INVENTION 281). The known flow dividers comprise a floating slide valve arranged in the body and forming two chambers therein. Communicating with the chambers are two inlet channels provided with throttles of a uniform cross-section mounted therein and connected to a fluid supply source. Also communicating with the chambers are two outlet channels connected to the motors, with the outlet channels being partially closed by the floating slide valve so that the edges of the valve form, with the outlet channels, two throttles of a variable cross-section at the outlet from the chambers.

The known throttles sufi'er from a considerable error in dividing the flow, which is mainly due to the hydrodynamic forces of the fluid medium flow passing through the chambers of the divider.

It is an object of the present invention to eliminate the above-mentioned disadvantages of the known devices.

It is the main object of the present invention to provide a throttle divider that would help improve the accuracy of dividing a fluid medium flow.

SUMMARY OF THE INVENTION In accordance with the present invention, outlet channels of the divider are interconnected by means of a channel in which a permanent hydraulic resistor is installed. It is expedient that a diaphragm throttle be used as the permanent hydraulic resister.

The main advantageous feature of this invention consists in that the permanent hydraulic resistor (throttle) introduced into the channel helps improve the accuracy of dividing the flow due to redistribution of the fluid medium from one working branch with higher pressure to the other working branch with lower pressure.

BRIEF DESCRIPTION OF THE DRAWING Presented hereinbelow is a detailed description of an examplary embodiment of the present invention, with due reference to the accompanying drawing which is a diagrammatic view illustrating a throttle divider according to the invention in a position in which the floating slide valve is in a neutral position.

DETAILED DESCRIPTION OF THE INVENTION The present throttle divider accommodates in a body 1, a floating slide valve 2 which defines in the body 1, two chambers 3 and 4. Communicating with the chambers 3 and 4 are respective inlet channels 5 and 6 which house uniform crosssection throttles 7 and 8 respectively serving to preset the value of the fluid medium flow rate from a fluid medium supply source (not shown in the drawing).

Also communicating with the chambers 3 and 4 are two outlet channels 9 and 10, respectively, with the outlet channels being connected to the motors being supplied (not shown in the drawing).

The outlet channels 9 and 10 are partially closed by the floating slide valve 2 whose end faces 11 and 12 together with the channels 9 and 10 at the outlet from the chambers 3 and 4 constitute variable cross-section throttles 13 and 14.

In order to improve the accuracy of dividing the flow, the outlet channels 9 and 10 are interconnected by means of a channel 15 in which a permanent hydraulic resistor 16 is installed, for instance, a diaphragm throttle. A diaphragm throttle is a local hydraulic resistance member defined by a thin washer (diaphragm) having a round opening. Pressure losses in such a throttle are in a quadratic dependence on the flow rate of the liquid and are practically independent of its viscosity.

The throttle divider according to the present invention operates in the following manner:

With the liquid being supplied to the divider and in the presence of equal counterpressure in the outlet channels 9 and 10, the slide valve 2 will assume in the body 1, a neutral position in which the throttles l3 and 14 have identical cross-sections. Fluid medium flows in the outlet channels 9 and 10 will be identical due to the similarity of the cross-sections of the throttles l3 and 14. If the pressure in the channel 9 becomes higher than that in the channel 10, the pressure upon the lefthand end face 11 of the slide valve 2 increases and the valve shifts to the right; accordingly, the cross-section of the throttle 13 will increase and that of the throttle 14 will decrease. The variations in the cross-sections of the throttles 13 and 14 bring about a balancing of pressures acting upon the end faces of the slide valve 2, and the valve assumes a new stable position. In addition to the fluid medium pressure upon the face ends of the slide valve 2, the latter is also affected by hydrodynamic forces of the fluid medium which occur in the throttles 13 and 14, the moment of time under consideration being characterized in that the hydrodynamic force of flow in the throttle 14 exceeds that in the throttle 13 due to the difference of pressure drops on the throttles. Under the eflect of difference of the hydrodynamic forces, the slide valve 2 opens the throttle 13 to a greater extent than required, and the channel 9 is supplied with more fluid medium than the channel 10.

The resultant error in the divider is compensated for by the overflow of fluid medium from the channel 9 with higher pressure to the channel 10 with lower pressure, via the throttle 16. The cross-section of the throttle 16 is such that the value of overflow be equal to half the error in dividing the fluid medium flow.

Therefore, the value of the cross-section of the throttle 16, whose calculation is presented hereinbelow, is of principal importance.

The difference of flow rates, A0, of the fluid medium passing through the throttles 13 and 14, is found from the formula: AQ=A 1 AP, where AP is the pressure difference of the fluid medium in the outlet channels 9 and 10; A is the coefficient determined from the formula g is gravity acceleration;

c is the coefficient of flow rate through the throttles 7 and 8;

f is flow areas of the throttles 7 and 8;

k is the coefficient expressing hydrodynamic forces as a function of structural parameters, slide valve-body and fluid medium properties, found experimentally (K 0.4-0.53);

'y is the specific gravity of the fluid medium; and

F is the slide valve area.

As pointed out hereinbefore, in order to balance the fluid medium flow rates in the channels 9 and 10, it is necessary that part of the fluid medium in an amount of AQ/2 overflow from the channel 9 to the channel 10.

The fluid medium flow rate q through the throttle 16 is found from the formula q= B m, where B is a coefficient found from the formula:

c, is the coefficient of fluid medium flow rate through the throttle l6; and

f is the flow area of the throttle 16.

In order to provide the accuracy of division, it is necessary to maintain the condition: q== (AQ/2).

Obviously, this equality will be observed if the coefficients A/2 and B are equal to each other.

Substituting their values into the above formulas, we obtain:

What I claim is: l. A throttle divider for a fluid medium flow, comprising a body, said body having two inlet and two outlet channels; a

floating slide valve having and faces, said valve being arranged in said body and defining therein two chambers communicating with said inlet and outlet channels; two uniform cross-section throttles installed in said inlet channels; two variable cross-section throttles defined at the outlet from said chambers by the end faces of the floating slide valve together with said outlet channels when the latter are partially closed by said slide valve; said body having a channel adapted to interconnect the outlet channels; and a permanent hydraulic resistor in said connecting channel.

2. The throttle divider as set forth in claim 1, wherein a diaphragm throttle serves as the permanent hydraulic resistor. 

1. A throttle divider for a fluid medium flow, comprising a body, said body having two inlet and two outlet channels; a floating slide valve having end faces, said valve being arranged in said body and defining therein two chambers communicating with said inlet and outlet channels; two uniform cross-section throttles installed in said inlet channels; two variable crosssection throttles defined at the outlet from said chambers by the end faces of the floating slide valve together with said outlet channels when the latter are partially closed by said slide valve; said body having a channel adapted to interconnect the outlet channels; and a permanent hydraulic resistor in said connecting channel.
 2. The throttle divider as set forth in claim 1, wherein a diaphragm throttle serves as the permanent hydraulic resistor. 